This invention relates to shadow mask type color picture tubes, and particularly to variations in the aperture patterns of shadow masks within such tubes having corrugated apertured masks.
In a recently suggested shadow mask type color picture tube disclosed in U.S. Pat. No. 4,072,876, issued to A. M. Morrell on Feb. 7, 1978, a mask corrugated in the horizontal direction is incorporated in combination with a flat or substantially flat faceplate. The apertures of the corrugated mask are slit-shaped and are aligned in vertical columns. In order to keep an acceptable pattern formation of the phosphor lines comprising the screen, the horizontal spacing between aperture columns and/or aperture width are varied as functions of the spacing variation between the mask and the screen. The present invention recognizes this prior art variation in aperture width and aperture column-to-aperture column spacing and provides another variation in aperture width in an apertured but unformed mask to compensate for deformation of the apertures that occur during formation of the mask into a corrugate shape.